1. Field of the Invention
The present invention relates to printing methods, printing apparatuses, printing systems, and storage media.
2. Description of the Related Art
Some types of printing apparatuses for printing images on media are provided with piezo elements for ejecting ink by being charged and discharged based on a plurality of drive signals. For example, JP 2000-52570A discloses a printing apparatus in which a plurality of types of drive pulses, each corresponding to a different ejection amount of ink, are divided up and included in two original drive signals, and in which printing is performed based on drive signals generated by selecting, from the two original drive signals, the drive pulses to be applied to the piezo elements.
The drive signals for driving the piezo elements are generated based on print data. Thus, the drive signals will be applied to the piezo elements when dots are to be formed in a region of pixels which make up an image, but they will not be applied in cases where dots are not to be formed. Incidentally, the drive signals are provided with drive pulses for ejecting the ink. These drive pulses, for example, raise or lower the voltage of the piezo elements above or below a reference voltage, which serves a predetermined reference, to cause the piezo elements to eject ink. For this reason, the start and the end of each drive pulse are equal to the reference voltage, and thus, the voltage of the piezo elements after ejecting ink becomes equal to the reference voltage. However, if there are contiguous pixels where dots are not formed, then no drive signals are applied to the piezo elements during that time, and thus the piezo elements are discharged and their voltage drops. If a drive signal is applied thereafter for causing dot formation to the piezo elements whose voltage has dropped below the reference voltage, then this will result in a much sharper change in voltage; compared to the ordinary change in voltage that should be caused by the drive signals. Such a sharp change in voltage may result in the piezo elements not operating properly.